//** jQuery Scroll to Top Control script- (c) Dynamic Drive DHTML code library: http://www.dynamicdrive.com.

//** Available/ usage terms at http://www.dynamicdrive.com (March 30th, 09')

//** v1.1 (April 7th, 09'):

//** 1) Adds ability to scroll to an absolute position (from top of page) or specific element on the page instead.

//** 2) Fixes scroll animation not working in Opera. 





var scrolltotop={

    //startline: Integer. Number of pixels from top of doc scrollbar is scrolled before showing control

    //scrollto: Keyword (Integer, or "Scroll_to_Element_ID"). How far to scroll document up when control is clicked on (0=top).

    setting: {startline:1, scrollto: 0, scrollduration:1000, fadeduration:[500, 100]},

    controlHTML: '<img src="image/gotop.png" style="width:80px; height:80px" />', //HTML for control, which is auto wrapped in DIV w/ ID="topcontrol"

    controlattrs: {offsetx:10, offsety:10}, //offset of control relative to right/ bottom of window corner

    anchorkeyword: '#top', //Enter href value of HTML anchors on the page that should also act as "Scroll Up" links



    state: {isvisible:false, shouldvisible:false},



    scrollup:function(){

        if (!this.cssfixedsupport) //if control is positioned using JavaScript

            this.$control.css({opacity:0}) //hide control immediately after clicking it

        var dest=isNaN(this.setting.scrollto)? this.setting.scrollto : parseInt(this.setting.scrollto)

        if (typeof dest=="string" && jQuery('#'+dest).length==1) //check element set by string exists

            dest=jQuery('#'+dest).offset().top

        else

            dest=0

        this.$body.animate({scrollTop: dest}, this.setting.scrollduration);

    },



    keepfixed:function(){

        var $window=jQuery(window)

        var controlx=$window.scrollLeft() + $window.width() - this.$control.width() - this.controlattrs.offsetx

        var controly=$window.scrollTop() + $window.height() - this.$control.height() - this.controlattrs.offsety

        this.$control.css({left:controlx+'px', top:controly+'px'})

    },



    togglecontrol:function(){

        var scrolltop=jQuery(window).scrollTop()

        if (!this.cssfixedsupport)

            this.keepfixed()

        this.state.shouldvisible=(scrolltop>=this.setting.startline)? true : false

        if (this.state.shouldvisible && !this.state.isvisible){

            this.$control.stop().animate({opacity:1}, this.setting.fadeduration[0])

            this.state.isvisible=true

        }

        else if (this.state.shouldvisible==false && this.state.isvisible){

            this.$control.stop().animate({opacity:0}, this.setting.fadeduration[1])

            this.state.isvisible=false

        }

    },

    

    init:function(){

        jQuery(document).ready(function($){

            var mainobj=scrolltotop

            var iebrws=document.all

            mainobj.cssfixedsupport=!iebrws || iebrws && document.compatMode=="CSS1Compat" && window.XMLHttpRequest //not IE or IE7+ browsers in standards mode

            mainobj.$body=(window.opera)? (document.compatMode=="CSS1Compat"? $('html') : $('body')) : $('html,body')

            mainobj.$control=$('<div id="topcontrol">'+mainobj.controlHTML+'</div>')

                .css({position:mainobj.cssfixedsupport? 'fixed' : 'absolute', bottom:mainobj.controlattrs.offsety, right:mainobj.controlattrs.offsetx, opacity:0, cursor:'pointer'})

                .attr({title:'Scroll Back to Top'})

                .click(function(){mainobj.scrollup(); return false})

                .appendTo('body')

            if (document.all && !window.XMLHttpRequest && mainobj.$control.text()!='') //loose check for IE6 and below, plus whether control contains any text

                mainobj.$control.css({width:mainobj.$control.width()}) //IE6- seems to require an explicit width on a DIV containing text

            mainobj.togglecontrol()

            $('a[href="' + mainobj.anchorkeyword +'"]').click(function(){

                mainobj.scrollup()

                return false

            })

            $(window).bind('scroll resize', function(e){

                mainobj.togglecontrol()

            })

        })

    }

}



scrolltotop.init()